Title: Catalysis Engineering, a Multi-level Approach
Catalysis plays an important role in Chemical Process technology. It is the enabling technology for good chemical manufacturing processes. Catalysis as a discipline is not just a part of chemistry or physics but it also is an engineering discipline. Chemical and physical aspects are often scale-independent but in the engineering disciplines usually, the scale of the operation plays a role. In catalysis, both scale- independent and scale-dependent phenomena play a role. The reaction mechanism and structure of the active sites are usually scale-independent. Reactor design studies belong to the realm of chemical reaction engineering and are clearly dependent on the scale. In catalysis good contact between reactants and active sites is essential and the contact is, in general, scale-dependent. An integrated approach of catalysis research and development covering aspects of (bio) chemistry and physics and chemical reaction engineering, referred to as ‘Catalysis Engineering ‘, is rewarding. It is appropriate to distinguish three levels, the microlevel, focusing on molecules and catalytic sites, the mesolevel focusing on the catalyst particle and the reactor, and the macro level, considering the total process. This lecture focuses mainly on multiphase (G/L) systems.
On the microlevel, the scale-independent information is collected. Thermodynamics defines the possible window of operation and heats of reaction. Information on kinetics is crucial. On the mesolevel, fascinating developments are visible in the field of structuring the space. On the one hand, at the scale of the particle, optimal porosity (optimal hierarchal pore networks consisting of micro-, meso- and macropores) is important. On the other hand, structured reactors often outperform conventional reactors such as packed bed reactors. Pros of fixed bed reactors are high catalyst loading, convenience, low cost and often the possibility to use commercially available catalysts; cons are maldistribution, leading to non-uniform concentration profiles and even hot spots, internal diffusion limitations that might lead to reduced activity and selectivity. In a packed bed reactor hydrodynamics and mass transfer rates are coupled to particle shape and size. In a structured reactor, more degrees of freedom exist. For instance, dependent on the design, particle sizes can be chosen to be much smaller than those in packed beds. Structured reactors allow a high efficiency, based on a high mass transfer rate at relatively low energy dissipation. The low energy dissipation is related with the hydrodynamics regime: laminar rather than turbulent. In addition, in multiphase flow under most practical conditions, the flow pattern is that of segmented flow (called Taylor flow), resulting in large gas-liquid mass transport rates. Structured reactors have a large potential in Process Intensification. From a chemical engineering point of view, the intrinsic scalability of these reactors is intriguing.
It is not wise to carry out the research aimed at developing a good catalyst separately from the reactor design. It does not make sense to develop the best possible catalyst and to use it in an unsatisfactory reactor. Both the catalyst and the reactor should be optimal. In addition, it does not make sense to develop a catalyst and reactors without attention to the macro- level. In all stages of process development or improvement, the (conceptual) process design should play a role.
The benefits of a multi-level approach will be illustrated with practical examples.
Jacob A. Moulijn is emeritus Professor of Chemical Engineering at the Delft University of Technology (19902007) and at the University of Amsterdam (1986-1990), visiting professor at several universities, including University of Delaware, USA, University of Gent, Belgium, National University of Singapore the University of Mumbai, India and Cardiff University, UK. During the nineties he was active in China for the UN-World Bank. He is active as consultant for several companies. He is the recipient of an Honorary Doctorate of the Åbo University, Finland and received several awards, including the BP Energy Price, and the NWO-STW ‘Simon Stevin Meesterschap’ award (2000). His research interests include: catalysis engineering, catalytic reactors, zeolitic membranes, kinetics, mass transfer, multiphase monolithic reactors, catalyst testing, petroleum conversion (Hydrotreatment, FCC, FischerTropsch), exhaust gas catalysis (soot from diesel engines, N2O removal, NO abatement, H2S removal, CFC conversion), selective hydrogenation, selective oxidation, photo- and electrocatalysis, catalyst synthesis by Atomic Layer Deposition (ALD), coal conversion (gasification, pyrolysis, combustion), and biomass conversion. He is (co-) author of over 750 technical papers, co-author of two books, editor of seven books, holder of several patents (reactor design, zeolitic membranes, catalyst development, biomass conversion).
Title: The roles of HCO3-/CO¬32- in catalytic oxidation processes
The fact that the redox potential of the couple CO3.-/CO32-, 1.57 V, is considerably lower than that of the OH./H2O suggests that in many catalytic oxidation processes carbonate might be involved. Indeed results point out that the Fenton reaction in the presence of HCO3- proceeds via:
Fe(H2O)62+ + HCO3- ⇌
FeII(CO3)(H2O)3 + H3O+ + 2H2O
FeII(CO3)(H2O)3 + OOH- ⇌
(CO3)FeII(OOH)(H2O)2- + H2O
FeIII(OH)3(H2O) + CO3.-
i.e. the active ROS in physiological media and in advanced oxidation processes is CO3.- and not OH..
Furthermore DFT calculations suggest that CO3.- is expected as the active species in photo-catalytic oxidation processes.
The observation that CuII(CO3)n(2n-2)-, CoII(CO3)n(2n-2)-and NiIIL2+ in the presence of bicarbonate are good electro-catalysts for water oxidation is due to:
Acknowledgement: This study was supported by a grant from the Pazy Foundation.
Dan Meyerstein is a Professor of Chemistry at Ariel University and Professor Emeritus at Ben-Gurion University in Israel. He Received his Ph.D. in 1965. He has over 350 papers. He was president of Ariel University and President of the Israel Chemical Society.
Title: Current state of the art on green synthesis of iron-based nanoparticles. Case study: Iron nanoparticles from Argentine yerba mate and green tea extracts useful for removal of pollutants in soil and water
A revision on the literature on green synthesis of iron-based nanoparticles and their application as nanotechnology for removal of pollutants from soil and water will be presented, highlighting the uncertainties about their chemical identity and efficiency for removal of pollutants. In addition, the need of further improvement in order to obtain stable nanoparticles of controlled size and morphology, conducive to large-scale synthesis of iron nanoparticles for environmental remediation and hazardous waste treatment applications will be stressed. As a study case, the preparation of iron-based nanoparticles synthesized from iron salts and water extracts (polyphenols) of powdered yerba mate (Ilex Paraguariensis Saint Hilaire) will be described. Yerba mate is highly consumed as an autochthonous tea in Paraguay, Uruguay, Brazil and Argentina. The nanomaterials have been completely characterized by XRD, Raman and Mossbauer spectroscopies and their applicability for Cr (VI) and As (III)/As (V) removal from polluted waters have been tested in laboratory tests with synthetic and real waters from Argentina and compared with other tea extracts such as green tea and commercial iron nanoparticles. The nanomaterials are low-cost, nontoxic and can be easily produced at large scale. They can be used for removal of other pollutants (e.g., mercury, uranium, lead, nitrate, halogenated hydrocarbons, pesticides such as 2, 4-D, etc.).
Prof. Litter has a Ph.D. in Chemistry (Buenos Aires University, Argentina), with postdoctoral studies at the University of Arizona, USA. She was head of the Division of Environmental Chemistry Remediation (National Atomic Commission of Argentina), Senior Researcher of the National Research Council and Full Professor at the University of General San Martín. She has more than 200 scientific publications in international journals, books, and book chapters. She received the Mercosur Prize in Science and Technology (2006 and 2011) and was President of the International Congress on Arsenic in the Environment (2014). She was designated pioneer on photocatalysis in Argentina (2016).
Title: Furfural, a valuable biobased platform
With an increasingly severe outlook for depleting oil-based resources, wood based biomass and especially plant waste rich in lignocellulosic feedstocks, appear to be the main alternative to produce many kinds of platform molecules such as furan derivatives. However, recent researches have shown that other kinds of carbohydrates as alginate derivatives could also be exploited as feedstocks for furfural production. As a molecule platform chemical, furfural permits to produce a large range of chemicals having different properties and utilities as solvents, plastics, fuel additives. Concerning the production of furfural, various homogeneous catalysts, solid acid catalysts and supported catalysts were explored in batch and in continuous flow by our group. Concerning the valorization route of furfural, the liquid phase catalytic hydrogenation was reported. Whereas molecular hydrogen is mostly used in industrial hydrogenation processes, recent studies also showed that alcohols can be used as reductants from which hydrides can be transferred catalytically to furfural. These two strategies: hydrogenation and transfer hydrogenation were developped in batch as well as in continuous flow for the production of value-added chemicals such as 2-methylfuran. Our works explore the catalytic behavior in batch and continuous flow of mono- and bimetallic metal catalysts (Cu, Pd, Pt, Ni) supported on various types of materials (microporous, mesoporous). Methodology, recycling, metal leaching will be discussed.
Prof. Dr. Christophe Len received his Ph.D. in 1995 from the Université de Picardie Jules Verne followed by a post-doctoral fellow at the University of Hull (England). In 1997, he became assistant Professor at UPJV and was promoted to full Professor in 2004 at the Université de Poitiers (France). In 2010, he moved as full Professor at the Université de Technologie de Compiègne – UTC (France). In 2017, he developed his research in Chimie ParisTech (France). He has published more than 175 original publications and review articles, 8 book chapters and 9 patents. Among recent awards and recognition to his scientific career, he was promoted Honorary Professor of the University of Hull, England (2012-2018), Honorary Life Fellow of Indian Society of Chemists and Biologists (ISCB, 2014), Fellow of the Association of Carbohydrate Chemists and Technologist of India (ACCTI, 2015) and Fellow of the Royal Society of Chemistry (FRSC, 2015). In 2017, he has been honored with 2017 Glycerine Innovation Award sponsored by the American Cleaning Institute and the National Biodiesel Board. Moreover, He is member of different editorial board: Molecules, Catalysts, Scientific Reports (Nature). His current research explores organic chemistry and catalysis applied to biomass.
Title: Application of Na3PO4/NaX catalyst for the side chain alkylation reaction of toluene with methanol
Styrene is a basic organic chemical raw material for synthetic rubber and plastics. At present, there are many ways to synthesize styrene in industry, but most of them are catalytic dehydrogenation of ethylbenzene. This process has many shortcomings such as long process and high energy consumption, which are not in line with the current concept of environmental protection and energy saving. The side-chain alkylation of toluene with methanol has many advantages, such as wide source of raw materials, short process flow, low energy consumption. Therefore, this reaction has become the focus of research.
A large number of studies have found that side-chain alkylation of toluene with methanol is a synergistic reaction on acid and base catalyst, and the catalyst needs to have suitable weak acid sites and base sites at the same time. In our recent research we found that moderate addition of cheaper Na3PO4 decreased the amount of middle acid and increased the strength and amount of middle base sites. Based on the unique role of Na3PO4 in regulating acidity and basicity, catalysts with different acidity and basicity were prepared in this paper and the relationship between the catalytic performance and the distribution of acid and base sites were investigated. The catalysts were characterized by XRD, SEM, FT-IR, BET, UV-Vis, NH3-TPD and CO2-TPD. It is found that the catalysts prepared by ion-exchange of Na3PO4 solution with NaX zeolite, the distribution of the acid-base sites changes with the concentration of Na3PO4 solution. While the catalyst prepared by a modified method which cannot be opened at present has a better performance for the side chain alkylation of toluene with methanol. The reason is that Na3PO4 and NaX can provide a suitable base site, a weak acid site respectively and they both form a suitable space structure required for the reaction. The reaction of toluene and methanol were very sensitive to the basicity and acidity of the catalyst, there were some competitive activations for toluene and methanol over middle acid and middle base sites. In the absence of strong acid sites on the catalyst, when the more middle base sites and the less middle acid sites there were on the surface of the catalyst, the more products of side-chain alkylation of toluene formed. If the middle base sites were enough, the stronger base sites there were on the surface of the catalyst, the more formaldehyde formed, so, the selectivity of styrene should be higher. That is, enough middle and strong base sites were both very important for the side-chain alkylation of toluene with methanol to styrene.
Faraz Ahmad is currently doing MS in Chemical Engineering from the School of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, Peoples Republic of China. Faraz is working as a research assistant in the Key Laboratory of Coal Science and Technology of Ministry of Education and Shanxi Province. His research topic is “Production of styrene and ethylbenzene by side-chain alkylation of toluene with methanol”. Specifically, his expertise is in the following area: catalyst preparation, characterization of catalysts. Previously in his BS, he has done a research project entitled “Production of Methanol from Coal”. Apart from an educational career he has two years of teaching experience in a reputable HEC recognized University in Pakistan.
Title: Synthesis and Application of Membrane-Grafted and Cyclodextrin Anchored Asymmetric Cinchona-Based Organocatalysts
In this work we continued our research in the field of application of organocatalysts in continuous mode performed in sustainable way.1 In the first part of this research, we introduce a sustainable membrane-based synthesis–separation platform for enantioselective organocatalysis. An azido derivatized cinchona-squaramide bifunctional catalyst was synthesized and subsequently grafted to the surface of a polybenzimidazole-based nanofiltration membrane. The favorable effect of the covalent grafting—due to the change in geometry and increased secondary interactions—on the catalytic activity due to conformational changes was confirmed by quantum chemical calculations. Asymmetric Michael and aza-Michael reactions of 1,3-dicarbonyl and indole, pyrazole, and triazole derivatives to β-nitrostyrene were performed with as high as 99% enantiomeric excess. This report on the enantioselective aza-Michael reaction of pyrazoles and triazoles opens new frontiers in the application of squaramide-based cinchona catalysts. A catalytic membrane cascade reactor was developed for an integrated synthesis–purification process allowing at least 98% product and substrate recovery, and quantitative in situ solvent recycling. The sustainability of the synthetic methodology was assessed through E-factor and carbon footprint.
In the next part, cinchona-thiourea and -squaramide catalysts were covalently anchored to inherently large, stable and well-defined permethyl-β-cyclodextrins, as well. These catalysts were used in batch and continuous mode with excellent enantioselectivity.
This research was funded by the New National Excellence Program of the Ministry of Human Capacities, grant number ÚNKP-19-4-BME-415, and the Janos Bolyai Research Scholarship of the Hungarian Academy of Science. It was also supported by the National Research, Development and Innovation Office (former OTKA, grant number K128473).
Jozsef Kupai works as an assistant professor at Budapest University of Technology and Economics Hungary, he delivers organic chemistry lectures and practices. He is the head of the Organocatalysis Research Group at the Department of Organic Chemistry and Technology. The expertise of the Kupai group (www.kupaigroup.com) members centers on the synthesis, application, and recovery of cinchona based organocatalysts. Dr. Kupai collaborates with Dr. Gyorgy Szekely at the University of Manchester. The Szekely Group is responsible for the process design encompassing flow reactors coupled with membrane purification.
Title: Optimization of Spent Caustic Wastewater Treatment of Jam Petrochemical Company by Wet Air Oxidation (WAO) method
Spent Caustic comes from a variety of sources. In these streams, sulfides and organic acids are removed from the production stream by transferring to the caustic phase. Hydrogen sulfide is consumed and the waste produced is usually a mixture of materials, which is referred to as the Spent Caustic Refinery. This wastewater cannot be recycled using conventional wastewater treatment methods, and methods such as burning, humidifying oxidation, wet oxidation by hydrogen peroxide and electrocoagulation or other specialized processes are used. In this study, the method of wet oxidation by air was used to purify this effluent in Jam Petrochemical Company. In order to optimize the purification, important factors influencing the purification efficiency were investigated, including factors such as temperature, pressure, time and pH. The design of optimization experiments was done by Design Express software. The optimization results showed that the temperature had the most effect on the removal efficiency, after which the pH and time had the most effect, respectively, and the effect of the pressure was not significant. Also, the parameters of pressure and time, time and pH had a significant interaction. In particular, the maximum removal rate (87%) was achieved for temperature of 250 ° C, 62 minutes, with pH 7 and 6 bar pressure.
Soroush karamian is a researcher in the R&D department in Jam Petrochemical Company(JPC) in Iran. Our research field focused on catalysts and green technology. This paper is a result of an experiment for Treatment of Jam Petrochemical Company by Wet Air Oxidation (WAO) method.
Title: Structural and morphological improvement of silica-alumina-phosphate nanostructure by hard template addition applied in green fuel production
The increases in the consumption of fossil fuels and environmental pollution caused by these fuels have been prompted researchers to produce renewable biodiesel fuels. Due to the high cost of biodiesel production, suitable catalyst design is highly efficient to increase efficiency and reduce biodiesel production time. The main objective of this research is to synthesize of Silica-Alumina-Phosphate nanostructure by hydrothermal method and to improve its structure in order to produce biodiesel by esterification reactions of free fatty acid. The fatty acid contained in the oil does not penetrate the Ce/SAPO-34 pores because of its large molecular size. To solve the penetration problem, the texture of the Ce/SAPO-34 was modified by the use of activated charcoal, and therefore meso and macro pores were formed in its structure. 4 wt.% of activated charcoal was determined to achieve a catalyst containing more meso and macro pores. Synthesized catalysts were evaluated by XRD, FESEM, BET/BJH analysis. The BET analysis showed that 4 wt.% of activated charcoal is the optimal amount of the hard template. The results of the reactor test showed that the synthesized nanocatalyst has the ability to convert 94% of the free fatty acid into biodiesel. The synthesized catalyst resulted in a conversion rate of 83% after 5 times of recovery, still maintaining its crystallinity.
Hossein Zainalzadeh is a Bachelor of Science degree student in Chemical Engineering at Sahand University of Technology and will complete his undergraduate degree on September 30, 2019. He was a member of the Nanotechnology and Science Committee for one year and teaching assistant (TA) in the "Fluid Mechanics" course for two semesters from October 1, 2018 to June 17, 2019. During his education, Hossein was one of the two undergraduate students who could enter the research centers as a research assistant (RA). Hossein has been working as a researcher under the supervision of Professor Mohammad Haghighi for three years. His research areas of interest are CO Oxidation, Hydrogen and Biodiesel production, designing and synthesis of nanostructure catalysts. Hossein’s B.Sc thesis focused on the biodiesel production over SAPO-34. Last summer, Hossein worked as an intern at Khoy Combined Cycle Power Plant. Presently he is planning to study M.Sc. in the related fields.
Title: Size-enlargement enhanced catalytic methodology for sustainable synthesis
Among organic transformations, catalyst assisted reactions are the most commonly performed processes. While in case of heterogeneous catalysts they are unambiguous, for homogeneous systems the laborious product purification and recycling of the high value catalysts still call for the design of more flexible and sustainable strategies. The membrane assisted recovery of homogeneous catalysts is feasible with low energy consumption, and its scale-up and implementation in continuous and hybrid processing are relatively straightforward. Still, the efficiency of catalyst separation depends on the absolute catalyst retention by the membrane and on the molecular weight gap between the catalyst and the other components (starting materials, product, side-product). Thus, the size-enlargement of the catalyst is usually required to achieve efficient retention and to avoid catalyst leaching in the membrane separation. This work presents nanofiltration enabled catalyst recycling methodology where the size-enlargement of the catalyst is achieved through covalent anchoring. Cinchona alkaloid based hydrogen bond donor organocatalysts (thiourea and squaramide) were attached to permethyl-β-cyclodextrin and applied in Michael reaction. For the asymmetric addition both alternative and conventional solvents were screened (up to 99% ee), and the enantioselectivities were correlated with the Kamlet-Taft parameters of the solvents. Continuous organocatalysis was performed in a coiled tube flow reactor connected to a membrane filtration unit (80 g L−1 h−1), allowing complete recovery of the catalyst and 50% solvent recycling. Further development of this catalysis-separation methodology could broaden the alternatives and facilitate the efficient production of enantiopure chemicals. The size-enlarged catalyst recovery procedure has the potential to be successfully applied in other catalytic fields as well, like electro-, or photocatalysis.
Péter Kisszékelyi is a fourth year PhD student at the George Oláh Doctoral School, Budapest University of Technology and Economics, Hungary. He works under the supervision of Dr. József Kupai in the Organocatalysis Research Group (www.kupaigroup.com) at the Department of Organic Chemistry and Technology. His research focuses on cinchona-based recyclable organocatalyst design and other sustainable catalytic methodologies.
Title: Immobilization of cinchona squaramide organocatalysts on poly(glycidylmethacrylate) and their application
Owing to their successful application in asymmetric reactions, cinchona-based organocatalysts are widespread in the field of homogenous organocatalysis. They are applied in asymmetric reactions such as Michael addition, Morita–Baylis–Hillman and Diels–Alder reactions with high yields and enantiomeric excesses. Since the recovery of homogeneous catalysts is essential for their economical application, immobilization on polymer support promises a solution for reusing them. Herein this work presents the preparation of a polymer carrier and, the synthesis and application of immobilized cinchona squaramides. Non-immobilized cinchona squaramides were tested in seven different solvents with excellent yields (up to 99%) and enantiomeric excesses (up to 91%),1 therefore this catalyst was chosen to immobilize on a carrier. As polymer support, poly(glycidyl methacrylate) (PGMA) microspheres were prepared by radical dispersion polymerization. As a result, polymer particles were obtained with narrow size-distribution (~1 m) furthermore, their resistance to solvents and mechanical damage was increased by subsequent cross-linking. By taking advantages of reactive epoxy-groups, cinchona squaramide was immobilized on PGMA via linker containing primer amino groups, which readily reacts with epoxides. Two PGMA immobilized catalysts were prepared (see Figure 1): in one, cinchona squaramide was immobilized so the linker connects at quinoline (left) while, in the other it connects at quinuclidine group (right). After their activity was compared in Michael addition reaction in batch using two different solvents, the one that performed better was chosen to use in a continuous flow reactor consisting of a column filled with the immobilized catalyst. The performance of the immobilized catalyst was examined in Michael addition reaction in the continuous flow reactor. This research was funded by the New National Excellence Program of the Ministry of Human Capacities, grant number ÚNKP-19-3-I-BME-397, ÚNKP-19-4-BME-415, and the Janos Bolyai Research Scholarship of the Hungarian Academy of Science. It was also supported by the National Research, Development and Innovation office (former OTKA, grant number K128473).
Sándor Nagy is a third year PhD student at the George Oláh Doctoral School, Budapest University of Technology and Economics, Hungary. He works under the supervision of Dr. József Kupai in the Organocatalysis Research Group (www.kupaigroup.com) at the Department of Organic Chemistry and Technology. His research focuses on design, synthesis, application and recycling of cinchona-based organocatalysts.
Title: Facile Synthesis and Photocatalytic Performance Evaluation of Nickel Oxide and Ni-Cu-Fe Oxides as Solar-Light-Driven Nanophotocatalysts
In the recent decades, large quantity of synthetic dyes has been released in the water resource through their usage in paper, textile, cosmetic, leather and other industries. They regarded as chemical pollutants which are profoundly poisonous and threats human and aquatic health. Hence, eliminating them from ground and surface water is significant problem. Advanced oxidation processes (AOPs) such as semiconductor-based photocatalytic degradation as “green” method due to free usage of solar irradiation, has attracted much attention since it is an eco-friendly, cost-effective and repeatable technology. Therefore, development of novel nanophotocatalysts with unique properties and high photocatalytic performance under visible light irradiation are of great interest to the researchers. In this research, we successfully synthesized nickel oxide and Ni-Cu-Fe oxides nanocomposite by the sono-hydrothermal method, respectively. The physical, chemical and optical properties of the synthesized photocatalysts were characterized by analyses like XRD, FESEM, BET-BJH, and DRS. Furthermore, the synthesized samples were evaluated for the removal of various organic dyes (malachite green, acid orange 7, and methyl orange) from aqueous solution under simulated solar light irradiation. BET-BJH analysis results showed that the synthesized samples due to the well-formed morphology had high specific surface area, and large pore volume. Also, DRS analysis represented that Ni-Cu-Fe oxide nanocomposite had narrower band gap energy compared to bare Nickel oxide. The photocatalytic results confirmed that the removal rate of MG over bare Nickel oxide and Ni-Cu-Fe oxide nanocomposite was 10% and 89%, respectively, in 120 min of simulated solar light luminance. This nanocomposite also degraded 64 and 58.5% of AO7 and MO, respectively, indicating its ability to the removal of a wide range of organic dyes. This outstanding performance of Ni-Cu-Fe oxide nanocomposite compared to bare Nickel oxide is attributed to the suitable adsorption ability of dye molecules and enhanced absorption capability of irradiated light resulting from the well-formed morphology, appropriate pore size distribution and geometry, proper specific surface area, and low band gap energy.
Iman Ghasemi was born in 1997. Iman earned a B.Sc. degree in chemical engineering from the Sahand University of Technology where he gained experience in water treatment by photocatalysis process under the supervision of Prof. Mohammad Haghighi. Since 2018 he has been joined Reactor and Catalysis Research Center and working on the nano photocatalyst synthesis and their applications in different organic dye degradation. Last summer, he worked for more than 4 months for “Azar Sahand Plastic Production Plant” as an intern in its quality control laboratory. His research interests include the “Green” synthesis of nanocatalysts and its application in air and water pollution control and treatment, and the study of their reaction mechanisms and kinetics.
Title: Ultrasound Assisted Dispersion of Magnesium Oxide on CeMCM-41 Nanocatalyst for Biodiesel Production from Waste Vegetable Oil
In this study, Mobil Composite Material No. 41 (MCM-41) used as the catalyst support for biodiesel production from waste cooking oil. Also, Si/Ce molar ratio of 10 introduced to the MCM-41 structure to prepare a modified bifunctional nanocatalyst with high stability and acidity. Then, ultrasound irradiation used to disperse MgO as active phase on the surface of as-fabricated support. The synthesized nanocatalysts were investigated using various techniques as follows: XRD, TEM, FESEM, and BET. The XRD patterns along with the results of BET analysis revealed the MCM-41 framework destruction while introducing Ce into the lattice. The particle size and size distribution of the nanocatalyst with Si/Ce=10 were subsequently determined by TEM and FESEM images. Biodiesel production carried out under following operational parameters to evaluate the catalytic performance of synthesized samples: T=70°C, catalyst loading=5 wt. %, methanol/oil molar ratio=9, and 6 h reaction time. Ce substitution in the support framework considerably enhanced the biodiesel conversion. The nanocatalyst with Si/Ce=10 demonstrated the extraordinary conversion of 94.3% compared to the nanocatalyst without Ce with 9.1% conversion. The reusability of the nanocatalyst with Si/Ce=10 studied during seven reaction cycles and biodiesel conversion reached to 88.7% at the end of the last cycle which demonstrates its significant stability.
Sahar Dehghani is Ph.D. of Chemical engineering from Sahand University of Technology in May 2019. She got M.Sc. degree of Chemical engineering in the field of catalysis from the Razi University in Feb. 2012. Also, she got her B.Sc. degree in chemical engineering from Mohaghegh Ardabili in Feb. 2008. She had taught the lab course of “Chemistry (I)” at Sahand University of Technology for three terms. She has been working in the Reactor and Catalysis Research Center (RCRC) at Sahand University of Technology since 21 Sep. 2013 under supervision of Professor Mohammad Haghighi. Her research focuses on biodiesel production by heterogeneous catalysts in both M.Sc. and Ph.D.
Title: Conventional vs. Microwave Heating in Combustion Synthesis of Ca-Mn Perovskite Used in MgO Nanocatalyst for Biodiesel Production
In the present article, MgO/Ca2Mn3O8 nanocatalyst was used in the transesterification process for production of green fuel from sunflower oil. Besides, the synthesis of the layered nanostructured Ca2Mn3O8 support was carried out by combustion method. The effect of two heating approaches including muffle furnace and microwave irradiation was investigated on the characteristics of calcium-manganese mixed oxide used as the support of the MgO active phase. Both of the synthesized nanocatalysts were characterized by different techniques such as XRD, FESEM and EDX. The nanocatalyst produced by the microwave irradiation combustion method scored the best performance. This nanocatalyst had the highest specific surface area (46.39 m2/g), and better pore volume distribution, too. It was also found that the nanocatalyst converted 96.7% of sunflower seed oil to fatty acid methyl esters (FAMEs), and exhibited better reusability in the same operating conditions compared to the sample synthesized with muffle furnace in five runs. This justified the positive influence of microwave irradiation on the catalytic properties.
Mehdi Mohammadpour holds a bachelor degree of science in Chemical Engineering from Azad University of Tehran. He was the director of education at several companies from July 16, 2013. He worked as an intern in PetroTech Company. At present, he is studying M.Sc. Chemical Engineering at Sahand University of Technology. His Master's thesis is about biodiesel (Green Fuel) production for Environmental purposes under the supervision of Professor Mohammad Haghighi and collaboration of Reza Shokrani (Ph.D. Student). Another area of his research focuses on Methane and Ethane Reforming. Mehdi is a member of Reactor and Catalysis Research Center (RCRC) from January 12, 2018 up to now.
Title: Photocatalytic Elimination of Antibiotic Ofloxacin over Plasmonic AgBr Anchored with Co-Cr Layered Double Hydroxide as Solar-Light-Driven Nanophotocatalyst
Currently, antibiotics, as non-biodegradable and emerging contaminants, are recognized as one of the most important environmental challenges. Photocatalysis process is an effective method for the degradation of resistant contaminants due to the low-cost and eco-friendly. In this study, the elimination of the antibiotic ofloxacin was investigated using the novel plasmonic AgBr anchored with Co-Cr layered double hydroxide (denoted as: AgBr-CoCrLDH-P) nanophotocatalyst with 3:1 weighted ratio under simulated sunlight, and to further evaluate, pure AgBr-P and CoCrLDH samples were synthesized and employed in the ofloxacin degradation. For 25 mg/L ofloxacin solution, the photocatalytic efficiency of CoCrLDH, AgBr-P and AgBr-CoCrLDH-P after 120 min irradiation was found 11.4%, 65% and 83.6%, respectively. XRD and FESEM analysis were used to characterize the photocatalysts. According to the results, the AgBr-CoCrLDH-P nanocomposite exhibited significantly enhanced photocatalytic performance due to a large specific area, low band gap and good charge separation.
Zahra Abdollahizadeh is M.Sc. student in Chemical engineering and Catalysis at Sahand University of Technology. She received her undergraduate degree in Chemical engineering from Azad University of Tabriz. She has been working in the Reactor and Catalysis Research Center (RCRC) at Sahand University of Technology since July 2018. Her field is catalyst, and she is the top student of this field. She is interested in environmental projects and is working on the photocatalytic degradation of the antibiotic pollutant from wastewaters. Her supervisor is Professor Mohammad Haghighi who is one of the prominent figures of this field. Zahra will be graduated next month and as soon as she is going to start her doctoral program.